Container for foamy liquid discharged in small amounts

ABSTRACT

A container in which air and a foamable liquid are passed through porous gas/liquid mixing members at which the foamable liquid and air are mixed together to be foamed so that the foam of the foaming liquid may be discharged from the container. The gas/liquid mixing members are porous films of which one is disposed at the bottom of a cylinder and at least two are disposed in a hollow piston inclusive of a hollow piston rod at predetermined spacing. A check valve is provided at the bottom of the cylinder. A liquid passage hole in communication with a downwardly extending liquid passage pipe is provided. A gas passage hole opens to a junction of the liquid passage pipe and liquid passage hole to form a gas/liquid mixing portion, and a second check valve is provided in the piston rod.

BACKGROUND OF THE INVENTION

This invention relates to a container for foamy liquid such as shampooto be discharged in small amounts.

DESCRIPTION OF THE PRIOR ART

Conventionally, containers for foamy liquid to be discharged in smallamounts are well known. Particularly, this type of container asdisclosed in many publications including Japanese Utility ModelApplication Laid-open No. 56-53066 comprises a container body, acylinder mounted in a mouth of the container body, a hollow pistonfitted, upwardly and downwardly movably, in the cylinder and having onits top a hollow piston rod, a porous gas/liquid mixing member disposedin a passage defined by the cylinder, hollow piston and hollow pistonrod, and a nozzle provided on the top end of the hollow piston rod, thepiston being operable to be moved upwardly and downwardly to cause afoamable liquid and air in the container body to pass through thegas/liquid mixing member at which the foamable liquid and air are mixedtogether to be foamed so that the foam of the foamy liquid may bedischarged from the container in small amounts.

Usually, the size of the foam of the foamy liquid discharged from thecontainer is desired to be small and to this end, the size of pores inthe gas/liquid mixing member through which the liquid and air pass mustbe small.

However, the gas/liquid mixing member used in the prior art container isa porous block having a long gas/liquid passage distance and if the sizeof pores is reduced, resistance against passage of the gas and liquid isincreased and it is difficult for the contents in the container todischarge. Accordingly, in the prior art container, the size of pores inthe gas/liquid mixing member is compelled to be large anddisadvantageously, a foamy liquid having small-sized foam can not beobtained.

Another container is also well known wherein pressurized gas such asfreon gas is fitted in a metal can and the contained liquid is mixedwith the gas to be foamed, thereby producing shaving foam. This knowncontainer, however, needs to be airtight and besides large-scaleequipments are required for filling the pressurized gas.

SUMMARY OF THE INVENTION

This invention contemplates elimination of drawbacks of the conventionalcontainers and has for its object to provide a container which canproduce a foaming liquid of relatively small-sized foam and which candispense with large-scale equipments for charging liquid contents.

According to the invention, to accomplish the above object, there isprovided a container wherein a plurality of gas/liquid mixing membersare provided which are formed of porous films, one gas/liquid mixingfilm being disposed at the bottom of the cylinder and at least twogas/liquid mixing films being disposed in the piston inclusive of thepiston rod at predetermined spacing, a check valve is provided in aliquid passage hole formed at the bottom of the cylinder, a downwardlyextending liquid passage pipe in communication with the liquid passagehole is provided, a gas passage hole opens to a junction of the liquidpassage pipe and liquid passage hole to form a gas/liquid mixingportion, and a second check valve is provided in the piston rod.

When the piston is moved downwards, a mixture of liquid and gas in thecylinder sequentially passes through the gas/liquid mixing filmsdisposed in the piston and opens the check valve provided in the pistonrod to discharge foam of a foaming liquid to the outside of thecontainer while the check valve provided in the liquid passage holeformed at the bottom of the cylinder is blocked. Subsequently, when thepiston is moved upwards, the check valve provided in the passage in thepiston rod is blocked and the liquid passage hole is opened so that theliquid and air in the container enter the cylinder through the liquidpassage pipe and gas passage hole and are pre-mixed at the gas/liquidmixing portion to produce a foamy liquid which in turn is drawn into thecylinder chamber.

Since, in accordance with the invention, the gas/liquid mixing membersare porous films and one gas/liquid mixing film is disposed at thebottom of the cylinder with at least two gas/liquid mixing filmsdisposed in the piston inclusive of the piston rod at predeterminedspacing, the distance across each gas/liquid mixing film through whichthe gas and liquid pass can be short to decrease resistance against thegas and liquid and the size of pores in the gas/liquid mixing films canbe relatively small. Consequently, the foam of foamy liquid can bereduced in size to take the form of creamy and uniform foam which iscomparable to that produced by the pressurized gas type container. Inaddition, the container of this invention can dispense with theconventional large-scale equipments for charging foamy liquid in thecontainer and it can be simplified in construction and manufactured atlow costs.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinally sectional front view illustrating anembodiment of a container according to the invention with a pistonraised.

FIG. 2 is a fragmentary sectional view illustrating another embodimentof the nozzle.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to FIG. 1, reference numeral 1 designates a container bodyhaving it mouth mounted with a cylinder 2, and a hollow piston 5 isfitted, upwardly and downwardly movably, in a chamber 3 of the cylinder2. Formed in the bottom of the cylinder 2 is an opening 6 in which aholder 8, adapted to hold a gas/liquid mixing film 16 to be describedlater and having a downward projection 7, is fitted so that the downwardprojection 7 blocks the opening 6 and protrudes into the containerbody 1. Formed in the downward projection 7 of the holder 8 is a liquidpassage hole 10 in which a check valve 11 comprised of a ball valve isprovided. The lower end of the liquid passage hole 10 merges into aliquid passage pipe 12 which extends from the lower portion of thedownward projection 7 and almost reaches the bottom of the containerbody 1. A lateral gas passage hole 13 is formed in the wall of thedownward projection 7 near a junction of the liquid passage pipe 12 andliquid passage hole 10, thus forming a gas/liquid mixing portion 15 nearthe junction.

A gas/liquid mixing film 16 made of a porous resin material such asnylon No. 66 and having porosity measuring a mesh size of 109 to 380 isheld on the holder 8 with its outer peripheral upper surface pushed downby a press ring 17.

The piston 5 has an upwardly extending hollow piston rod 18 having a topend connected with a nozzle 20. Provided in a passage 4 of the hollowpiston rod 18 is a check valve 21 comprised of a ball valve. Agas/liquid mixing film 23 similar to the gas/liquid mixing film 16 abutsagainst the back of the top of piston 5 forming the base of the pistonrod 18 with its outer peripheral lower surface pushed up by a press ring24. A gas/liquid mixing film 25, like the gas/liquid mixing films 16 and23, is held by a projection 26 of the nozzle 20 in the passage 4 andabove the check valve 21. The nozzle 20 is received in a cylinder 32extending upwards from a cap 31 for the container body 1 and is normallyurged upwards by a spring 33 inserted between the bottom of nozzle 20and the top surface of cap 31.

The operation of this embodiment will now be described.

Referring to FIG. 1 showing the state before start of use, when thepiston 5 is pushed down in opposition to the spring 33, the check valve11 blocks the liquid passage hole 10 and the check valve 21 opens thepassage 4, with the result that air in the cylinder chamber 3 passesthrough the gas/liquid mixing films 23 and 25 and a liquid dischargepassage in the nozzle 20 connected to the piston rod 18 and isdischarged to the outside.

Subsequently, the push-down force on the piston 5 is removed andrestoring force of the spring 33 causes the piston 5 to recover theoriginal position. At that time, the check valve 21 blocks the passage 4and the check valve 11 opens the liquid passage hole 10, with the resultthat liquid and air in the container body 1 entering the liquid passagepipe 12 and gas passage hole 13, respectively, are pre-mixed at thegas/liquid mixing portion 15, passed through the liquid passage hole 10and gas/liquid mixing film 16 at which they are further mixed together,and drawn into the cylinder chamber 3.

The mixture of liquid and gas thus drawn into the piston chamber 3 isready to be discharged as a foaming liquid.

Under this condition of container, in order to discharge the foamyliquid, the piston 5 is again pushed down in the manner describedpreviously to place each of the cooperative members in the samecondition as described previously. But in this phase, in addition toair, the drawn mixture in the form of foamy liquid is sequentiallypassed, under the influence of compression of the cylinder chamber 3 bythe piston 5, through the gas/liquid mixing films 23 and 25 at which themixing of the foamy liquid with air is promoted to uniform the foam, andas a result small-sized creamy foam is discharged through the nozzle 20to the outside.

Subsequently, the above operation is repeated until the desired amountof foaming liquid is discharged.

FIG. 2 shows another embodiment of this invention. This embodimentdiffers from the foregoing embodiment only in that a gas/liquid mixingfilm 35, like the gas/liquid mixing films 16, 23 and 25, is additionallyprovided in the tip end opening of the nozzle 20. Thus, the number ofthe gas/liquid mixing films used is increased to 4 in this embodiment,thereby further promoting the size reduction of the foam of the foamyliquid to be discharged.

The location of the gas/liquid mixing films 23, 25 and 35 in theforegoing embodiments is described for illustrative purpose only andthey may be disposed at desired locations in the piston. Further, thenumber of the gas/liquid mixing films is not limited to 2 to 4 but maybe changed to 4 or more, thus permitting detailed design alternationsand modifications within the framework of the invention.

What is claimed is:
 1. A container for foamy liquid discharged in smallamounts comprising a container body, a cylinder mounted in a mouth ofsaid container body, a hollow piston fitted, upwardly and downwardlymovably, in said cylinder and having on its top a hollow piston rod,porous gas/liquid mixing members disposed in a passage defined by saidcylinder, hollow piston and hollow piston rod, and a nozzle provided onthe top end of said hollow piston rod, said piston being operable to bemoved upwardly and downwardly to cause a foamable liquid and air in saidcontainer body to pass through said gas/liquid mixing members at whichthe foamable liquid and air are mixed together to be foamed so that thefoam of the foaming liquid may be discharged from said container insmall amounts, wherein said porous gas/liquid mixing members areprovided which are formed of porous films, one gas/liquid mixing filmbeing disposed at the bottom of said cylinder with at least twogas/liquid mixing films disposed in said piston inclusive of said pistonrod at predetermined spacing, a check valve is provided in a liquidpassage hole formed at the bottom of said cylinder, a downwardlyextending liquid passage pipe in communication with said liquid passagehole is provided, a gas passage hole opens to a junction of said liquidpassage pipe and liquid passage hole to form a gas/liquid mixingportion, and a second check valve is provided in said piston rod.
 2. Thecontainer according to claim 1, wherein one of said gas/liquid mixingfilms is also provided in said nozzle.
 3. The container according toclaim 1 or 2, wherein said piston is normally urged upwards by a spring.